Mesenteric venous thrombosis is a blood clot in the major veins that drain blood from the intestine.

Mesenteric venous thrombosis affects the mesenteric veins, one of two veins through which blood leaves the intestine. The condition interrupts blood supply to the intestine and can result in intestinal damage.

There are a variety of causes of mesenteric venous thrombosis. Many of the diseases that lead to this condition cause inflammation of the tissues surrounding the veins. The following conditions can lead to inflammation and mesenteric venous thrombosis:

• Pancreatitis
• Diverticulitis
• Appendicitis (less common)
• Liver disease with cirrhosis

Patients who have blood clotting disorders that make the blood more likely to stick together (clot) have a higher risk for mesenteric venous thrombosis.

In most cases, mesenteric venous thrombosis is a condition that slowly gets worse. Symptoms include long-term abdominal pain, which may get worse after eating. Sudden (acute) mesenteric venous thrombosis can cause severe abdominal pain that continues to get worse. The patient may also have vomiting and diarrhea.

A CT scan is the main test used to diagnose mesenteric venous thrombosis. An ultrasound of the abdomen and mesenteric veins may also be done.